[Choux]

I've always thought that all white pasta contains the same ingredients... it is only the shapes that are different.

Is that correct?

[shygrneyzs]

Not necessarily. There are rice flour pastas, various kinds of wheat based pastas, and soy based pastas, just to name a few.

[Choux]

Of the wheat based pastas, is the only difference in product the shape?

[GlindaofOz]

The wheats can be different.

Some people make whole wheat pastas though typically pasta is made with a semolina flour.

[shygrneyzs]

Here is a fairly comprehensive description of wheat flours and others flours:
Cook's Thesaurus: Wheat Flours